1. Field of the Invention
The present invention relates to a method and apparatus for processing output files, and more specifically, to creating an output file that is highly portable to other systems and devices.
2. Description of Related Art
Printing refers to the reproduction of words and pictures on a page or document. Today, the high volume production machines of the major printing processes are the presses, which use plates (or other types of image carriers) to transfer the ink onto the paper or substrate. These processes are often used to support markets such as commercial printing, magazines, newspapers, catalogs, books, business forms, greeting cards, maps, labels, packaging, and other printed products.
With the development of digital image processing, new vistas have opened up for plate making and film making processes used in conventional printing presses operations. Instead of being dependent on the prepress operations of film making, image carriers can be made directly from the same digital data without the need for films and assembling them into plate layouts. Photography is gradually being replaced by digital imaging systems. Dry processless films are often used today. Digital cameras and Photo CDS are decreasing the need for scanners. Prepress for many printing processes is migrating to device independent desktop publishing hardware and software.
Furthermore, with digital imaging, digital printing systems may be used to improve the productivity, quality, and efficiency of many printing operations. Many digital printing systems use a plateless printing process. Common plateless digital printing processes include electrophotography, ink-jet, and thermal transfer, etc. Digital printing systems are often desirable over printing press processes because (1) most of the equipment are suitable for an office environment (2) its capabilities of variable printing from impression-to-impression; and (3) requires less manual skills than printing on conventional plate presses.
As the printing industry transitions from conventional printing press operations to digital prepress operations and digital printing operations to take advantage of the technological advances made in digital imaging, it is possible to provide a more automated printing process.
It is particularly advantageous to provide a single output file that is compatible with various output devices such as a Postscript.RTM. file. PostScript is a registered trademark of Adobe Systems. PostScript is a page description language developed by Adobe Systems to describe an image for printing (i.e., both text and graphics). Today, PostScript is widely adopted by the printing industry, that is, virtually every application program running in every desktop computer outputs PostScript and virtually every printer of every type, including some sophisticated prepress and even press systems, accept PostScript-coded files. The primary advantage of PostScript is device independence (i.e., images are not defined according to the characteristics of a particular device but independently).
However, problems can arise, even with "working" PostScript files, if the file is transferred to another operating system or printed on another output device. One tool that Adobe provides to create a PostScript file that is highly portable between systems and devices and makes post-processing possible is referred to as the Document Structuring Conventions (DSC). DSC provides a convention for commentary and organization of PostScript files that make PostScript files highly portable. DSC comments are an extension to the actual PostScript page description language and have become an integral part of PostScript. Implementing these DSC conventions is often regarded as an important step towards creating "good" PostScript files. By providing a highly portable output file, the output file can be used by various applications for further processing (e.g., off-site vendor applications, pre-press applications, etc.).
Today, Adobe provides a tool referred to as the "Distiller" for converting a multiple-page PostScript file without DSC comments into a multiple-page PostScript file that is DSC compliant. However, the Distiller does not have the capability to add DSC comments while assembling a collection of input files into a single output file, or correcting for any erroneous comments (e.g., DSC comments or some other convention for creating highly portable files).